Actually the earlier CPSC requirements were simple and straightforward. I was very much involved in translating & interpreting them for the Italian manufacturers we represented at the time.

There was no issue of inconsistancey because the CPSC didn't tell manufacturer what to do. They simply identified a number of issues & stated their objection and the general type of solution they wanted. But they only identified goals and objectives, and tests for measuring compliance. They left it to manufacturers to design to meet those objectives, which is why various makers came up different answers.

Also keep in mind, that the rules applied only to complete bikes sold at retail, and not to components sold separately as upgrades. They also allowed exceptions for "special purpose" or bicycles intended for competition.

In the case of brake QRs, not all manufacturers went to in the lever solutions. Some elected to reduce the throw of caliper or hanger mounted QR systems, though that approach depended on the proper adjustment.

At the time, I wasn't a fan of many of the requirements but, overall, considering the quality of what was being sold at the time, it was something that had to happen.

In general, the approach to regulation (not only for bicycles) in that era, where regulators identified a problem, and said "fix that however you want" was much better than the type of micro-management by regulation we see today.